1. Field of the Invention
The present invention relates to a stable comprising a floor, upright walls bounding said floor, in which walls one or more fans are present, and a roof covering a space bounded by said floor and said walls, in which roof means for exhausting spent air are present, wherein said spent air is used for controlling the temperature of the air to be supplied. The present invention furthermore relates to a method for controlling the climate in such a stable.
2. Description of the Prior Art
From Netherlands Patent Application 8002341, which is laid open to public inspection, a similar method is known for controlling climatological aspects in a work space. An air guidance system is mounted in the uppermost part of a work space, via which system fresh air is transported from the rear side wall to the front side wall. The air guidance system is furthermore provided along the whole length of the side wall with a tubular element, in which outlet openings are provided. One drawback of using such a system in a work space is the fact that the amount of air flowing from said outlet openings and the temperature thereof are the same at every position in said work space. Thus, precise control or metering of the amount of air and control of the temperature thereof at any position in the work space is not possible, which can be considered to be a drawback, especially from the points of view of health and economy.
Such a stable is also known from Dutch patent No. 1000001, which stable is provided with ventilating means, which are capable of drawing in outside air, and which can be driven in an oscillating manner by driving means, such that an air flow is effected over part of the floor. The spent air that is produced in the stable is exhausted to the outside air without any after-treatment. According to said Dutch patent, ventilation of the animals which are present in the stable takes place with fresh outside air, which would lead to a significant improvement as regards the well-being of the animals, since odour and heat are quickly discharged from the animals"" surroundings, thus giving them ma sense of cooling rather than of heat. Thus, the number of animals dying due to accumulation of harmful gases and heat could be reduced considerably. From practice it has become apparent, however, that the well being of said animals has improved insufficiently, because the outside air being supplied in cold weather conditions causes illness among the animals. Besides, the energy consumption is high in such a stable, since there is no re-use of useful spent flows. In addition, the emission of ammonia is high, due to the presence of the manure on the stable floor. According to said Dutch patent, the harmful emission of ammonia is indeed slightly reduced by supplying cold outside air, but a drawback of using such cold outside air is the fact that it causes illness among the animals, which is undesirable.
From German Offenlegungsschrift DE-A-3131655 a method and a device for a climate control system are furthermore known, wherein the fresh outside air is passed through a heat exchanger, which is fed with stable air, in order to raise the temperature of said outside air. In addition to that, an amount of heated outside air is passed through a second heat exchanger and discharged to the stable floor. One drawback of such a climate control system is the fact that neither the amount of the air to be supplied to the stable nor the temperature thereof can be controlled in dependence on the presence of animals at a particular location in the stable. Consequently, such a robust climate control system will not be suitable for intensive rearing farms, for example poultry rearing farms, because of the temperature sensitivity of the animals and their susceptibility to illness, in particular due to draught.
The objective of the present invention is to construct a stable in such a manner that a significant saving on energy costs can be realised.
Another objective of the present invention is to construct a stable in such a manner that the emission of ammonia is minimized.
Another objective of the present invention is to provide a climate control system for a stable, which system provides favourable living conditions for the animals.
Another objection of the present invention is to provide a method and a device which make it possible to create climatologically favourable conditions at any location, independently of the conditions at other locations.
The present invention as referred to in the introduction is characterized in that said fan supply conditioned air essentially at stable floor level, wherein the amount of air to be supplied and the temperature thereof can be controlled for each fan individually.
The term xe2x80x9cessentially at stable floor levelxe2x80x9d must be understood to mean the height of the animals, which height will be less than 1.5 m in practice. The air is supplied for the purpose of optimizing the living conditions of the animals, so that it is desirable to supply air to the location where the animals are present, that is, on the stable floor. In practice the animals, for example chickens, will scatter at random over the floor. It happens frequently, however, that all the animals gather in a particular part of the stable, for example as a result of a shock reaction. This means that the production of CO2 and heat will be high at that part of the stable, which harmful effects are overcome by the present invention, since the amount of the air to be supplied and the temperature thereof can be controlled for each fan individually. After all, there is no need to supply air to a part of the stable where no animals are present. Thus, the fan will supply a sufficient amount of cold air at the location where there is a high concentration of animals.
As a result of the presence of the animals on the stable floor, the energy content of the spent air is such that said energy can be used advantageously for controlling the temperature of the air to be supplied to the stable floor. The term xe2x80x9cfor each fan individuallyxe2x80x9d is to be understood to include the embodiment wherein a number of fans disposed side by side are driven simultaneously, for example. In other words, the present invention makes it possible to set climatologically independent conditions in particular parts of the stable, so that zones are created which can be controlled independently of each other.
Although it is known from Dutch patent NO. 1000001 to have the control of the ventilating means take place in an automated manner, taking into account the inside temperature, the outside temperature and other parameters which are essential for conditioning purposes, for example, it is not known from said Dutch patent to use the spent air for controlling the temperature of the air to be supplied to the stable floor.